Since the discovery of fullerenes, a number of their poly-substituted derivatives have been reported. For example, polyalkylfullerene derivatives can be prepared by reacting fullerenes with organic alkyl lithium or alkyl Grignard reagents and then with alkyl halides, or directly with organic radicals. See Wudl, et al., ACS Symp. Ser. 1992, 481, 161 and Krusic, et al., Science 1991, 254, 1183. On the other hand, enones react with fullerenes to afford polycycloalkylfullerene derivatives. See Wilson, et al., J. Am. Chem. Soc. 1993, 115, 8495. As another example, polyalkylaminofullerene derivatives is synthesized by reacting fullerenes with alkyl amine. See Hirsch, et al., Angew. Chem. Int. Ed. Engl. 1991, 30, 1309. Some of the above-mentioned reactions, however, suffer from low yields and ion reaction time.
An aspect of this invention relates to a fullerene derivative of the following formula:
F(xe2x80x94E)n(xe2x80x94R1)p(xe2x80x94R2)q
F is a fullerene core. E is E1, E2, or E3. E1 is Y1,Y2-amino, (Y1,Y2-alkyl)-amino, Y1,Y2ethylenediamino, (dihydroxymethyl)alkylamino, (X1,X3-aryl)amino, or X1,X3-aryloxy. E2 is Y1,Y2-alkoxy, (Y1,Y2-amino)alkoxy, (Y1,Y2,Y3-aryl)oxy, (dihydroxyallkyl)-aryloxy, (Y1,Y2,Y3-alkyl)amino, (Y1,Y2,Y3-aryl)amino, dihydroxyalkylamino, Y1,Y2,Y3-alkoxy, (trihydroxyalkyl)alkoxy, (trihydroxyalkyl)alkylamino, (dicarboxyalkyl)amino, (Y1,Y2,Y3alkyl)thio, (X1,X3-aryl)thio, (Y1,Y2-alkyl)thio, (dihydroxyalkyl)thio, Y1,Y2-dioxoakyl, or tri-(Y1,Y2,Y3-methylaminocarboxyethyl)methylamino. E3 is ((glycosidyl)oxoheteroaryl)amino, ((glycosidyl)oxoaryl)amino, (X1,X2,X3-heteroaryl)amino, (X1-diarylketone)amino, (X,X1-oxoaryl)amino, (X,X1-dioxoaryl)amino, (Y1-alkyl,Y2-alkyldioxoheteroaryl)amino, (Y1-alkyl,Y2-alkyldioxoaryl)amino, (di(Y1,Y2-methyl)dioxoheteroaryl)amino, (di(Y1,Y2-methyl)dioxoaryl)amino, ((glycosidyl)heteroaryl)amino, ((glycosidyl)aryl)amino, ((carboxylacetylalkyl)oxo-heteroaryl)amino, ((carboxylacetylalkyl)oxoaryl)amino, ((isopropylaminohydroxy-alkoxy)aryl)amino, (X1,X2,X3-alkylaryl)amino, (X1,X2,X3heteroaryl)oxy, (isopropylaminohydroxyalkyl)aryloxy, (X1,X2,X3-oxoheteroaryl)oxy, (X1,X2,X3-oxoaryl)oxy, (X1,Y1-oxoheteroaryl)oxy, (X1-diarylketone)oxy, (X,X1oxoaryl)oxy, (X1,X2-dioxoaryl)oxy, (Y1,Y2,di-aminodihydroxy)alkyl, (X1,X2-heteroaryl)thio, ((tricarboxylalkyl)ethylene-diamino)alkoxy, (X1,X2-oxoaryl)thio, (X1,X2-dioxoaryl)thio, (glycosidylheteroaryl)thio, (glycosidylaryl)thio, Y1-alkyl(thiocarbonyl)thio, Y1,Y2-alkyl(thiocarbonyl)thio, Y1,Y2,Y3-alkyl(thiocarbonyl)thio, (Y1,Y2-aminothiocarbonyl)thio, (pyranosyl)thio, cysteinyl, tyrosinyl, (phenylalainyl)amino, (dicarboxyalkyl)thio, (aminoaryl)1-100amino, (pyranosyl)amino, (Y1-aminoaryl)1-100amino, (amino(sulfoaryl))1-100amino, peptidyl, thymidinyl, uridinyl, guanosinyl, adenosinyl, cholesteryl, or biotinylallcoxy. X is halide. Each of X1, X2, and X3, independently, is xe2x80x94Y1, xe2x80x94Oxe2x80x94Y1, xe2x80x94Sxe2x80x94Y1, xe2x80x94NHxe2x80x94Y1, xe2x80x94COxe2x80x94Oxe2x80x94Y1, xe2x80x94Oxe2x80x94COxe2x80x94Y1, xe2x80x94COxe2x80x94NHxe2x80x94Y1, xe2x80x94COxe2x80x94NY1Y2, xe2x80x94NHxe2x80x94COxe2x80x94Y1, xe2x80x94SO2xe2x80x94Y1, xe2x80x94CHY1Y2, or xe2x80x94NY1Y2. Each of Y1, Y2, and Y3, independently, is xe2x80x94Z or xe2x80x94Bxe2x80x94Z. B is xe2x80x94Raxe2x80x94Oxe2x80x94[Si(CH3)2xe2x80x94Oxe2x80x94]1-100, C2-100 alkyl, C6-40 aryl, C7-2000 alkylaryl, C7-2000 arylalkyl, (C1-30 alkyl ether)1-100, (C6-40 aryl ether)1-100, (C7-2000 alkylaryl ether)1-100, (C7-2000 arylalky ether)1-100, (C1-30 alkyl thioether)1-100, (C6-40 aryl thioether)1-100, (C7-2000 alkylaryl thioether)1-100, (C7-2000 arylalkyl thioether)1-100, (C2-50 alkyl ester)1-100, (C7-2000 aryl ester)1-100, (C8-2000 alkylaryl ester)1-100, (C8-2000 arylalkyl ester)1-100, xe2x80x94Ra=l xe2x80x94COxe2x80x94Oxe2x80x94(C1-30 alkyl ether)1-100, xe2x80x94Raxe2x80x94COxe2x80x94Oxe2x80x94(C6-40 aryl ether)1-100, xe2x80x94Raxe2x80x94COxe2x80x94Oxe2x80x94(C7-2000 alkylaryl ether)1-100, xe2x80x94Raxe2x80x94COxe2x80x94O (C7-2000 arylalkyl ether)1-100, (C4-50 alkyl urethane)1-100, (C14-60 aryl urethane)1-100, (C10-2000 alkylaryl urethane)1-100, (C10-2000 arylalkyl urethane)1-100, (C5-50 alkyl urea)1-100, (C14-60 aryl urea)1-100, (C10-2000 alkylaryl urea)1-100, (C10-2000 arylalkyl urea)1-100, (C2-50 alkyl amide)1-100, (C7-60 aryl amide)1-100, (C8-2000 alkayl amide)1-100, (C8-2000 arylalkyl amide)1-100, (C3-30 alkyl anhydride)1-100, (C8-50 aryl anhydride)1-100, (C9-2000 alkylaryl anhydride)1-100, (C9-2000 arylalkyl anhydride)1-100, (C2-30 alkyl carbonate)1-100, (C7-50 aryl carbonate)1-100, (C8-2000 alkylaryl carbonate)1-100, (C8-2000 arylalkyl carbonate)1-100, xe2x80x94Raxe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94(C1-30 alkyl ether, C6-40 aryl ether, C7-2000 alkylaryl ether, or C7-2000 arylalkyl ethel )1-100, xe2x80x94Raxe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94(C2-50 alkyl ester, C7-60 aryl ester, C8-2000 alkylaryl ester, or C8-2000 arylalkyl ester)1-100, xe2x80x94Raxe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94(C1-30 alkyl ether, C6-40 aryl ether, C7-2000 alkylaryl ether, or C7-2000 arylalkyl ether)1-100xe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Raxe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94(C2-50 alkyl ester, C7-60 aryl ester, C8-2000 alkylaryl ester, or C8-2000 arylalkyl ester)1-100xe2x80x94Rcxe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Raxe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94(C1-30 alkyl ether, C6-40 aryl ether, C7-2000 alkylaryl ether, or C7-2000 arylalkyl ether)1-100, xe2x80x94Raxe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94(C2-50 alkyl ester, C7-60 aryl ester, C8-2000 alkylaryl ester, or C8-2000 arylalkyl ester)1-100, xe2x80x94Raxe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94(C1-30alkyl ether, C6-40 aryl ether, C7-2000 alkylaryl ether, or C7-2000 arylalkyl ether)1-100xe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Raxe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94(C2-50 alkyl ester, C7-60 aryl ester, C8-2000 alkylaryl ester, or C8-2000 arylalkyl ester)1-100xe2x80x94Rcxe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Raxe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94Hxe2x80x94(C2-50 alkyl amide, C7-60 aryl amide C8-2000 alkylaryl amide, or C8-2000 arylalkyl amide)1-100, xe2x80x94Raxe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94(Rb or Arxe2x80x94Rbxe2x80x94Ar)xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94(C2-50 alkyl amide, C7-60 aryl amide, C8-2000 alkylaryl amide, or C8-2000 arylalkyl amide)1-100. Each Z, independently, is xe2x80x94Gxe2x80x94D, wherein G is xe2x80x94Raxe2x80x94, xe2x80x94Raxe2x80x94Arxe2x80x94, xe2x80x94Arxe2x80x94Raxe2x80x94, or xe2x80x94Arxe2x80x94. D is xe2x80x94H, xe2x80x94OH, xe2x80x94SH, xe2x80x94NH2, xe2x80x94NHOH, xe2x80x94SO3H, xe2x80x94OSO3H, xe2x80x94CO2H, xe2x80x94CONH2, xe2x80x94CONHNH2, xe2x80x94CH(NH2)xe2x80x94CO2H, xe2x80x94NHxe2x80x94CH2xe2x80x94CO2H, xe2x80x94P(OH)3, xe2x80x94PO(OH)2, xe2x80x94Oxe2x80x94PO(OH)2, xe2x80x94Oxe2x80x94PO(OH)xe2x80x94Oxe2x80x94PO(OH)2,xe2x80x94Oxe2x80x94PO(O31)xe2x80x94Oxe2x80x94CH2CH2NH3+, xe2x80x94Oxe2x80x94PO(Oxe2x88x92)xe2x80x94Oxe2x80x94CH2CH2xe2x80x94N+(CH3)3, -glycoside, -oligosaccharide, xe2x80x94CO-glycoside, xe2x80x94CO-oligosaccharide, xe2x80x94OCH3, xe2x80x94OCH2(CHOH)4xe2x80x94CH2OH, xe2x80x94OCH2(CHOH)2xe2x80x94CH2OH, xe2x80x94COxe2x80x94OCH2(CHOH)4xe2x80x94CH2OH, xe2x80x94C6H3(OH)2, xe2x80x94N(CH2CO2H)2, xe2x80x94COxe2x80x94N(CH2CO2H)2, xe2x80x94COxe2x80x94NHxe2x80x94C(CH2CH2CO2H)3, xe2x80x94COxe2x80x94NHxe2x80x94C(CH2CH2OH)3, xe2x80x94[CH2xe2x80x94CH(CO2Ra)]1-100 xe2x80x94H, xe2x80x94NH3+, xe2x80x94N+H2Ra, xe2x80x94N+HRaRb, or xe2x80x94N+RaRbRc. Each of Ra, Rb, and Rc, independently, is C1-20 alkyl and Ar is aryl. R1 is xe2x80x94OH or xe2x80x94NH2. R2 is xe2x80x94Oxe2x80x94 (an epoxide formed by joining 2 fullerene carbon atoms and an oxygen atom). n is 1-30; p is 1-20; and q is 0-10. Note that when R1 is xe2x80x94NH2, q is 0.
Another aspect of this invention relates to a method preparing a fullerene derivative of the formula F(xe2x80x94E)n(xe2x80x94R1)p(xe2x80x94R2)q. The method includes the steps of obtaining a polynitrofullerene or polycyclosulfated fullerene intermediate (see Examples 1 and 2); contacting the intermediate with a nucleophilic agent to produce a fullerene derivative of the formula F(xe2x80x94E)n (see Examples 3-26), and contacting the resulting fullerene derivative with a hydroxylating or an aminating agent to produce a fullerene derivative of the formula F(xe2x80x94E)n(xe2x80x94R1)p(xe2x80x94R2)q, wherein each of F, E, R1, R2, p, q, and n has been defined above (see Examples 28 and 29).
By the term xe2x80x9calkylxe2x80x9d is meant a straight chain that contains 1-30 carbon atoms, or a branched hydrocarbon chain of 3-30 carbon atoms, or cyclic hydrocarbon groups containing 3-30 carbon atoms, or otherwise indicated. These alkyl groups may also contain one or more double bond or triple bond and the cyclic alkyl groups may contain one or more heteroatoms, which are, typically, nitrogen, oxygen, or sulfur. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, amyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, pentadecyl, icosyl, alkyl, 2-butenyl, 2-pentenyl, 3-hexenyl, 4-decenyl, 5-nonadecenyl, 2-butnyl, 3-octnyl, 5-octadecnyl, cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, norbornyl, isobornyl, cyclopentyl-methyl, cyclohexylmethyl, 1- or 2-cyclohexylethyl, cyclo-pentenyl, cyclohexenyl, cycloheptenyl, cyclo-octenyl, tetra-hydrofuranyl, tetrahydropyranyl, piperidinyl, morpholino and pyrrolindinyl groups.
As used herein, the term xe2x80x9carylxe2x80x9d refers to C6-40 aromatic rings. These moietes may also be fused rings and can be fused with aryl or heteroaryl which is as defined below. Fused rings are rings that share a common carbon-carbon bond. Typically aryl groups include phenyl, naphthyl, biphenyl, indazolyl, phenanthryl, and anthracyl.
By the term xe2x80x9cheteroarylxe2x80x9d in this disclosure is meant C6-40 aromatic rings that contain one or more heteroatoms as defined above. These moieties may also be fused ring Examples of heteroaryl groups include pyridyl, pyrazinyl, pyrimidyl, furyl, pyrrolyl, thienyl, thiazolyl, oxazolyl, imidazolyl, coumarinyl, indolyl, benzofuranyl, benzthiazolyl, benzothienyl, and benzothiadiazolyl.
As used herein, the term xe2x80x9chalidexe2x80x9d is defined as fluoro, chloro, bromo, or iodo. The terms xe2x80x9cpolynitro-fullerenesxe2x80x9d and xe2x80x9cpolycyclosulfated fullerenesxe2x80x9d in this disclosure have the formulas, Fxe2x80x94(NO2)n and Fxe2x80x94(SO4)n, respectively, in which n is at least 2. The term xe2x80x9cnucleophilic agentxe2x80x9d is defined as an electron-rich species that donates electrons in a reaction. Examples of nucleophilic agents that can be employed in the preparation of polyorganofullerene derivatives include amine, phenol, alkoxide, organothiolate, carbanion, organoamide anion, thiol, amino acid, and thiol carbamate anion. Note that the just-mentioned nucleophilic agents can be unsubstituted or substituted with other functional groups. Examples of substituted nucleophilic agents include 1,4-naphthoquinonyl 1-amine, tyrosine, dihydroxypropylthiol, and the like. For instance, polynitrofullerene can react with the nucleophilic agent dihydroxypropylthiol to produce the corresponding polyorganofullerene derivative poly(dihydroxypropyl-mercapto)fullerene. See example 19 below. By the term xe2x80x9chydrolysisxe2x80x9d is meant a water molecule, under basic or acidic condition, attacks and breaks a susceptible bond of a compound. Bases are generally employed as hydrolyzing agents herein for the preparation of polyhydroxy-organofullerene derivatives and sodium hydroxide is a preferred hydrolyzing agent in this disclosure.
The structures of many of the moieties mentioned above are shown below within the pair of parentheses following each of the moieties: alkyl ether (xe2x80x94Rxe2x80x94Oxe2x80x94), aryl ether (xe2x80x94Arxe2x80x94Oxe2x80x94), alkylaryl ether (xe2x80x94Rxe2x80x94Arxe2x80x94Oxe2x80x94), arylalkyl ether (xe2x80x94Arxe2x80x94Rxe2x80x94Oxe2x80x94), alkyl thioether (xe2x80x94Rxe2x80x94Sxe2x80x94), aryl thioether (xe2x80x94Arxe2x80x94Sxe2x80x94), alkylaryl thioether (xe2x80x94Rxe2x80x94Arxe2x80x94Sxe2x80x94), arylalkyl thioether (xe2x80x94Arxe2x80x94Rxe2x80x94Sxe2x80x94), alkyl ester (xe2x80x94Rxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94Rxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94R1xe2x80x94COxe2x80x94Oxe2x80x94R2xe2x80x94Oxe2x80x94COxe2x80x94, or xe2x80x94R1xe2x80x94Oxe2x80x94COxe2x80x94R2xe2x80x94COxe2x80x94Oxe2x80x94), aryl ester (xe2x80x94Arxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94Arxe2x80x94COxe2x80x94O, xe2x80x94Ar1xe2x80x94COxe2x80x94Oxe2x80x94Ar2xe2x80x94Oxe2x80x94COxe2x80x94, or xe2x80x94Ar1xe2x80x94Oxe2x80x94COxe2x80x94Ar2xe2x80x94COxe2x80x94Oxe2x80x94), alkylaryl ester (xe2x80x94Rxe2x80x94Arxe2x80x94Oxe2x80x94Oxe2x80x94 or xe2x80x94Rxe2x80x94Arxe2x80x94COxe2x80x94Oxe2x80x94), arylalkyl ester (xe2x80x94Arxe2x80x94Rxe2x80x94Oxe2x80x94COxe2x80x94 or xe2x80x94Arxe2x80x94Rxe2x80x94COxe2x80x94Oxe2x80x94), alkyl urethane (xe2x80x94R1xe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94R2xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94), aryl urethane (xe2x80x94Ar1xe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94Ar2xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94), alkylaryl urethane (xe2x80x94R1xe2x80x94Arxe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94R2xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Rxe2x80x94Ar1xe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94Ar2xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94, or xe2x80x94R1xe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94Arxe2x80x94R2xe2x80x94Arxe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94), arylalkyl urethane (xe2x80x94Arxe2x80x94R1xe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94R2xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94AR1xe2x80x94Rxe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94Ar2xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94, or xe2x80x94Ar1xe2x80x94Oxe2x80x94COxe2x80x94NHxe2x80x94Ar2xe2x80x94Rxe2x80x94Ar2xe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94), alkyl urea (xe2x80x94R1xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94R2xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94), aryl urea (xe2x80x94Ar1xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94Ar2xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94), alkylaryl urea (xe2x80x94R1xe2x80x94Arxe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94R2NHxe2x80x94COxe2x80x94NHxe2x80x94, xe2x80x94Rxe2x80x94Ar1xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94Ar2xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94, or xe2x80x94R1xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94Arxe2x80x94R2xe2x80x94Arxe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94), arylalkyl urea (xe2x80x94Arxe2x80x94R1xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94R2xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94, xe2x80x94Ar1xe2x80x94Rxe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94Ar2xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94, or xe2x80x94Ar1xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94Ar2xe2x80x94Rxe2x80x94Ar2xe2x80x94NHxe2x80x94COxe2x80x94NHxe2x80x94), alkyl amide (xe2x80x94Rxe2x80x94NHxe2x80x94COxe2x80x94, xe2x80x94Rxe2x80x94COxe2x80x94NHxe2x80x94, xe2x80x94R1xe2x80x94COxe2x80x94NHxe2x80x94R2xe2x80x94NHxe2x80x94COxe2x80x94, or xe2x80x94R1xe2x80x94NHxe2x80x94COxe2x80x94R2xe2x80x94COxe2x80x94NHxe2x80x94), aryl amide (xe2x80x94Arxe2x80x94NHxe2x80x94COxe2x80x94, xe2x80x94Arxe2x80x94COxe2x80x94NHxe2x80x94, xe2x80x94Ar1xe2x80x94COxe2x80x94NHxe2x80x94Ar2xe2x80x94NHxe2x80x94COxe2x80x94, or xe2x80x94Ar1xe2x80x94NHxe2x80x94COxe2x80x94Ar2xe2x80x94COxe2x80x94NHxe2x80x94), alkylaryl amide (xe2x80x94Rxe2x80x94Arxe2x80x94NHxe2x80x94COxe2x80x94, xe2x80x94Rxe2x80x94COxe2x80x94NHxe2x80x94Arxe2x80x94NHxe2x80x94COxe2x80x94, or xe2x80x94Rxe2x80x94NHxe2x80x94COxe2x80x94Arxe2x80x94COxe2x80x94NHxe2x80x94), arylalkyl amide (xe2x80x94Arxe2x80x94Rxe2x80x94NHxe2x80x94COxe2x80x94, xe2x80x94Arxe2x80x94COxe2x80x94NHxe2x80x94Rxe2x80x94NHxe2x80x94COxe2x80x94, or xe2x80x94Arxe2x80x94NHxe2x80x94COxe2x80x94Rxe2x80x94COxe2x80x94NHxe2x80x94), alkyl anhydride (xe2x80x94Rxe2x80x94COxe2x80x94Oxe2x80x94COxe2x80x94), aryl anhydride (xe2x80x94Arxe2x80x94COxe2x80x94Oxe2x80x94COxe2x80x94), alkylaryl anhydride (xe2x80x94Rxe2x80x94Arxe2x80x94COxe2x80x94Oxe2x80x94COxe2x80x94 or xe2x80x94Rxe2x80x94COxe2x80x94Oxe2x80x94COxe2x80x94Arxe2x80x94COxe2x80x94Oxe2x80x94COxe2x80x94), arylalkyl anhydride (xe2x80x94Arxe2x80x94Rxe2x80x94COxe2x80x94Oxe2x80x94COxe2x80x94 or xe2x80x94Arxe2x80x94COxe2x80x94Oxe2x80x94COxe2x80x94COxe2x80x94Oxe2x80x94COxe2x80x94), alkyl carbonate (xe2x80x94Rxe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94), aryl carbonate (xe2x80x94Arxe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94), alkylaryl carbonate (xe2x80x94Rxe2x80x94Arxe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94or xe2x80x94Rxe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94Arxe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94), and arylalkyl carbonate (xe2x80x94Arxe2x80x94Rxe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94 or xe2x80x94Arxe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94Rxe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94). Note that the di-substitution pattern on Ar can be para, meta, or ortho.
One can employ polynitrofullerenes, Fxe2x80x94(NO2)n, or polycyclosulfated fullerenes, Fxe2x80x94(SO4)n, described herein as intermediates for preparation of various fullerene derivatives (as shown in the following examples). The use of these intermediates allows the reactions to proceed at a fast rate under a mild condition. These fullerene derivatives that are synthesized from polynitrofullerenes or polycyclosulfated fullerenes can, in turn, be used to produce fullerene-grafted polymers. See U.S. Pat. No. 5,635,581. In addition to acting as starting materials for polymers, these derivatives have also been demonstrated to be useful free-radicals scavengers. See U.S. Pat. No. 5,648,523.
Other features and advantages of the present invention will be apparent from the following description of the preferred embodiments, and also from the appending claims.
Described below are various methods for synthesizing some of the polyorganofullerene derivatives via polynitro-fullerenes or polycyclosulfated fullerenes described herein.
Polynitrofullerene derivatives, Fxe2x80x94(NO2)n, which act as a reactive intermediate in this invention, can be prepared by one of the following methods:
a) A method for producing Fxe2x80x94(NO2)n, involve reacting fullerene, F, with nitrogen dioxide radicals, NO2, which are generated from sodium nitrite, NaNO2, and concentrated HNO3. See Chiang et al., Tetrahedron 1996, 52(14), 4963. The structure of Fxe2x80x94(NO2)n has been characterized to contain at least 4 nitro groups.
b) Fxe2x80x94(NO2)n, wherein n is 4, can also be prepared from reacting fullerene with dinitrogen tetraoxide, N2O4 in carbon disulfide solution. See Cataldo et al., Fullerene Sci. and Techno. 1997, 5(1), 257.
c) Yet another method for the preparation of Fxe2x80x94(NO2)n can be done by reacting fullerene with nitrogen dioxide gas, which is generated from a mixture of NaNO2 and FeSO4 in aqueous H2SO4. See Sarkar et al., J. Chem. Soc., Chem. Commum. 1994, 275.
d) Still another method for the preparation of Fxe2x80x94(NO2)n can be done by reacting fullerene with fuming nitric acid. See Hamwi et al., Fullerene Sci. and Techno. 1996, 4(5), 835.
Polycyclosulfated fullerene derivatives, Fxe2x80x94(SO4)n, which can also be employed as an effective intermediate in this invention, can be prepared by reacting fullerene and neat fuming sulfuric acid in the presence of an oxidant (e.g., P2O5, V2O5, or SeO2). The structure of the product has been characterized to consist at least 4 cyclosulfated units.
Fullerene derivatives of this invention can be synthesized in general by reacting Fxe2x80x94(NO2)n or Fxe2x80x94(SO4)n with a nucleophilic agent, Exe2x80x94H, (e.g., primary and secondary organoamino compound, alkoxide, organothiolate, organophenol compound, carbanion, organoamide anion, thiocarbamate ion, and the like) in a non-reactive solvent, such as tetrahydrofuran. A base may be needed in some reactions (see examples below) to produce a nucleophilic anion of Exe2x80x94H that is of enough strength to undergo the substitution reaction. Some examples of such a base include 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU, 1,5-diazabiacyc-[4.3.0]non-5-ene (DBU), and lithium diisopropyl-amine (LDA).
Alternatively, fullerene derivatives of this invention can be prepared by reacting Fxe2x80x94(NO2)n or Fxe2x80x94(SO4)n with a lithium salt of Exe2x80x94H, which is generated by reacting Exe2x80x94H with lithium triethylborohydride (Super-Hydride(copyright)) in tetrahydrofuran or other non-reactive solvents. Examples of lithium salts of Exe2x80x94H include, but are not limited to, lithium organoamino compounds, lithium organothiolate, lithium organophenol.
A fullerene derivative, e.g., F(xe2x80x94E), can further undergo nucleophilic replacement reactions with an agent, e.g., NaOHxe2x80x94H2O, to generate a hydroxylated fullerene derivative that may contain epoxide (xe2x80x94Oxe2x80x94). See Examples 28 and 29 below. Similarly, an aminated fullerene derivative, e.g., F(xe2x80x94E)(NH2)p can be prepared by treating a fullerene derivative, e.g., F(xe2x80x94E), with ammonia gas. See Examples 3 and 6 for procedures on reacting a fullerene derivative with ammonia gas. The number of E in a fullerene derivative can be adjusted by controlling the stoichiometry of the starting materials. Note that the symbol, n, used in each term does not necessary have the same number as the same symbol used in another term in this disclosure.